51单片机（普中板）蜂鸣器控制

蜂鸣器通过震荡脉冲控制

1，尝试发声

#include <REGX52.H>
#include "Delay.h"


sbit buzzer = P2^5; // 蜂鸣器端口
unsigned int i;  //演奏时长
void main()
{
    while(1)
    {
        for (i=0 ; i < 500; i++)
        {
            buzzer =! buzzer;
            Delay(100);  //100*100us = 10000us = 10ms = 0.01s = 100hz
        }
    }
}

 2，演奏音乐（演奏完停止）

#include <REGX52.H>
#include "Timer0.h"
#include "Delay.h"

// 蜂鸣器端口
sbit buzzer = P2^5;
# define step 250

//索引与频率对照表
unsigned int FreqTable[]={
    0,
    63628,63731,63835,63928,64021,64103,64185,64260,64331,64400,64463,64528,
    64580,64633,64684,64732,64777,64820,64860,64898,64934,64968,65000,65030,
    65058,65085,65110,65134,65157,65178,65198,65217,65235,65252,65268,65283,
};
// 音符集
unsigned char Music[] = {
    13,4,
    13,4,
    20,4,
    20,4,
    22,4,
    22,4,
    20,4+4,
    0,4,
    18,4,
    18,4,
    17,4,
    17,4,
    15,4,
    15,4,
    13,4+4,
    0xff  // 截至符
};
// 
unsigned int FreqSelect,MusicSelect;

void main()
{
    Timer0_Init(); // us
    while(1)
    {
        if (Music[MusicSelect] != 0xff)
        {
                FreqSelect = Music[MusicSelect];
                MusicSelect ++;
                
                Delay1ms(step/4*Music[MusicSelect]);
                MusicSelect ++;
                
                TR0 = 0;
                Delay1ms(5);
                TR0 = 1;
        }
        else
        {
            TR0 = 0;
            while(1);
        }
        
    }
}

// 定时其中断函数
void Timer0() interrupt 1
{    
    if (FreqTable[FreqSelect])
    {
        TH0 = FreqTable[FreqSelect] / 256;                //设置定时初始值
        TL0 = FreqTable[FreqSelect] % 256;                //设置定时初始值
        buzzer =! buzzer;
    }

}

3，演奏音乐（循环播放）

#include <REGX52.H>
#include "Timer0.h"
#include "Delay.h"

// 蜂鸣器端口
sbit buzzer = P2^5;
# define step 250

//索引与频率对照表
unsigned int FreqTable[]={
    0,
    63628,63731,63835,63928,64021,64103,64185,64260,64331,64400,64463,64528,
    64580,64633,64684,64732,64777,64820,64860,64898,64934,64968,65000,65030,
    65058,65085,65110,65134,65157,65178,65198,65217,65235,65252,65268,65283,
};
// 音符集
unsigned char Music[] = {
    13,4,
    13,4,
    20,4,
    20,4,
    22,4,
    22,4,
    20,4+4,
    0,4,
    18,4,
    18,4,
    17,4,
    17,4,
    15,4,
    15,4,
    13,4+4,
    0xff  // 截至符
};
// 
unsigned int FreqSelect,MusicSelect;

void main()
{
    Timer0_Init(); // us
    while(1)
    {
        if (Music[MusicSelect] != 0xff)
        {
                FreqSelect = Music[MusicSelect];
                MusicSelect ++;
                
                Delay1ms(step/4*Music[MusicSelect]);
                MusicSelect ++;
                
                TR0 = 0;
                Delay1ms(5);
                TR0 = 1;
        }
        else
        {
            MusicSelect  = 0;
        }
        
    }
}

// 定时其中断函数
void Timer0() interrupt 1
{    
    if (FreqTable[FreqSelect])
    {
        TH0 = FreqTable[FreqSelect] / 256;                //设置定时初始值
        TL0 = FreqTable[FreqSelect] % 256;                //设置定时初始值
        buzzer =! buzzer;
    }

}

音符与频率对照表：